Tampa, Florida -- The New Tampa teen who allegedly planned a Columbine-like attack on Freedom High School will spend 15 years behind bars.

The judge decided Jared Cano, 18, meant what he said about planning to launch a deadly plot on the first day of school last year. Cano's sister, Alexandria, gasped and had to be removed from the courtroom in tears.

Cano had pleaded no contest in the case.

He entered the courtroom Wednesday, smiling at his family and taking deep breaths.

In August 2011, Tampa police got a tip Cano was planning an attack on Freedom High. They found a manifesto, maps, and bomb-making materials in his apartment.

"Kill anybody in there. After that, it's just in the parking lot and just shoot anyone there," he said in a self-made video-tape played in court again during the sentencing hearing.

In that chilling, profanity-laced video, Cano himself details the plan: how he would move room to room, leaving a trail of death and mayhem, detonating bombs, shooting administrators and students as they ran for cover.

He defies authority. He tells people not to blame his mom for what he planned to do.

Afterward, the judge heard from Freedom High's school police officer, Samuel Rojka, who said "Students were quite terrified. The administration was terrified."

In Cano's defense, a psychologist testified 90% of such threats are a hoax. The risk of Cano actually committing a act of violence, said Richard Carpenter, "are relatively low."

Family members then spoke about the teen's troubled youth. He came from a broken family and had mental health issues. Cano teared up as his mother Michelle called him a loving child.

He smiled as his sister spoke about him in glowing terms.

Then Cano himself spoke, asking Judge Kimberly Fernandez for a second chance.

"I don't want to be the bad guy. I want to be the good guy. The state ain't gonna make an example. They're gonna put me in prison. Let me make an example. I had a bad life. Let me change it around and do something good, not bad. Don't make me the poster child for something evil. Let me be the poster child for something good. Let me do right. Give me a chance to do something right. To make my family proud. I don't want all these people to think I'm crazy, trying to kill everybody. I want people to look at me as someone who was wrong and changed... and did something right."

Judge Fernandez had the option of sentencing Cano as a juvenile, youthful offender or an adult.

She ruled Cano an adult and handed him a sentence of 15 years in prison, followed by 10 years probation. It was a judgment that stunned Cano, who shaked his head and gasped.